SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dd4f4d0abb98de620eaa7f24470ceac535f5b5fe2e097302ea5e368a94f5b5d' 
  AND token = 'fjUnyDRDLSVQbjIqc1eHllpPZ84tQKlkfnVsaugay+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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