SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a35fea2afd97ec129b9346471ae4e850ec36d035031f30cffddf02c779a493' 
  AND token = 'OYlMtfr9w6no3gZSqMWGxHRsG2Tqddjpa1DbIKuRuh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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