SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c312dc9562990ac33a68f1ec1833964b22ef88d4e5e97f2a3bad7087c468f12' 
  AND token = 'YLwFO2ntcrHBU/BMvd1/qH/qhmUHVe0jB4JeMvAFTMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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