SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c2741d1a7af34bd1c0712df32ced8c16649fe2df5c25959b2dd54e9d4e3a57' 
  AND token = 'zyJbL+iXJjKHrutuuTJVB0yldaWPGsxU2Pq7IdKslD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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