SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '14324a0c26d183fa0ce5d384666201a2e7f65975d80e8fc1c8a145b7128a3901' 
  AND token = 'bDB/n+BncKNgqfmJJ9YnPjmEhVjQCQeeZt+kFxO8IqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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