SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e1c7255504b866bade011f08de952f1b2f60f527690d5fca0c82c2484875237' 
  AND token = '5QEJMW7ttJW2SUhHwgp+8aNKlE6oorKyIBDwPcKJoFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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