SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '33408a31416023d1a0b5b30132024f42dd6eaac0e363fdae7f1c431caf2109c4' 
  AND token = 'rlvXBy+85d1iprBvZigCI7FzRMASUasFHGwpKQyHYDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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