SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ae5e779398da4b246041e280f841b933127788ca95953941d5d41c41491a135' 
  AND token = 'niL4tJVbv2kI2ZM6YHsvYXd49a+vQyemepTnxox6GvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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