SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1351b42156bff939bf09a5d4cf8dde18d9aa53483ae74f6aea84f4422086b14' 
  AND token = 'nBSqCF5nXjcy2nH7tnZGx/T/aNss42JlIQpB1FWaAlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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