SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7480bcdae928d5482c70b5397c439afd76d3ceebeb024124dedf4ac8ca897be8' 
  AND token = 'h8qpbxtWEhO4AQGKogfnbaT+M2bmOdsLphHmn5GyOFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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