SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d161b86d08b9e93c7f9fb1716f158180678330f94d9d3ed2b79cedeb3160a9a' 
  AND token = 'Qp9qJwn0ockzzFl6SWaHC07ePj+JVjMTgzrSwYZ2Rrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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