SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af8b2c90f16e3178a86b51b0de76af4a4e19db8844a5b0d67727a306457100d5' 
  AND token = 'geultfAYyYklsp/9M4FsPY4y6Q9yPZCa67jNLSLOjAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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