SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a4ab20f6b46b12e49e29cd7ff895d26d552d0a07d9ac58e1f9743c5c210c5d9' 
  AND token = '+hZ/FHSqsW223nJYbAxe0XU66rwS1qOj0L2mHD9upCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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