SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ccb9be962711b1759f4e9d48f5b83e16d01625c4c8a523c34d13a920d46cd1e' 
  AND token = 'fosOi++2qxSVQY8DaE+cXhU+OUlV//iIzJePL1V6PzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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