SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1995a184821cbbc69c33f2120015ddb3fa6b47dbff7f328605ded7279fe5ba01' 
  AND token = 'ciNWt5aH5bIMIzktWldS5sbSdN3pM9OCzlodznO9pIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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