SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1073128d1bc63d575cfff384388c2c0982ef3a93007e083b94b84f7d76630994' 
  AND token = '4p7MJUvrgqNv1Am6XQsP7I64vHM4A+dCxg2s9YZWzyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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