SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ad4e59c4de40bdad010168a381d6f9098d6238cb60b004378a973817ded277b' 
  AND token = 'BJ257BaS4HcSEjWVY+wXAGjPkVRS1EZ3qy+9QewchFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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