SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f1c6b8935fab8176391eb422436849caafc8205e7b40e0294918aecd1aac7acf' 
  AND token = 'WNXqOWogJoWAiDa/vsX26YPtVg+ciOOUozfJM+nUye8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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