SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4bb11fb9dd47463a938a80ebe598b5224c8b09c30daf9de8c431bba4c7888597' 
  AND token = '+FX3AyrsU3WO0YVJs5UkAaHn5q8Tsp0nwVhjrAMbfgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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