SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99fce1b683c98c6ae2c9499c95a0267294246189422f58efccdf26db2e85dd67' 
  AND token = 'o6D79qNhjz3B1FPn93xvRny7PffHtRVUPHZlylzTrJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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