SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864686c7a8cd24698ac8ea30cb2e69ca146ae83d5efb2f4aa01aecaea60990c3' 
  AND token = 'N5GiKc3iAeAmV98kuYZFS4kHlEl42RZwjh7rCeM52ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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