SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '018770c17623dc6367daf5b93cc9282d320ab409765bdfa906df29f6e9e1920e' 
  AND token = 'DYcdOus8m1DTwJBDCTIANTr/xcLOb6fLQv/BXRz3DP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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