SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18abcc587a0d2924170d7aecfba1d69816043f18ef49fd9db6906a22f12da151' 
  AND token = 'amp88aBcgCeQXQqLDeTD6Od2ZIFvBRy1COnc0ncEmbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}