SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9bab6502abede004b77dd8f3985dd936bc5147ce9faef57c9d39d49562278c0' 
  AND token = '2l3BRNDkXCMuvzJ9VAIiy5cHr/4gela0DA96hawaVD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}