SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9aa032f677cfae12d7b552348d2acef7ca19d61a2d240daf6e6c226a830acdd' 
  AND token = 'ZgTDLF5looikuyFK+EOQlLDXCjNRLTeUUnmz+ZGZpV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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