SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e38ebc921c43730fbb0e70bc0e9f6362c918a18f9b6d3becb2ba0ead669930ff' 
  AND token = 'oPG8TUwMXlShIutoREve4VpLhU566icPSQkJDGL+mBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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