SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef25e48449faf795a8215b1dd424a9f7e7de8e869d146dd23737d9d570897b38' 
  AND token = '/atA7lk3bAJnUa4ayJD+41T2Dj251wqjlgTeUQOISoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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