SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '092b317cf6f824661a975d878e93ae5dc055e28a848d573ba4701e767a75b55a' 
  AND token = 'pNC0A/oSEzkvWPNLq1Gnp4/T+2sfryedYl+S+DVBi3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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