SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0e2a1ef17222b6c59e699518b2d00020ce0366509001ad5001c46c0c6f35fb1c' 
  AND token = 'zrvLFL3XV8v5hR4CN3yUMW8UX7ZIlIm4Du9aPQVT7wA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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