SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43f94d8dbf8540910e320c2b1e9512a6b68a1cd8ea8043045cbaafed172567eb' 
  AND token = 'ylW7Uqzvo+egLuAW+XCgCFquLxNlDhO2tpJ4IYC0SqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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