SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fdcf2762909acd0f5918cc9cdd122019539b481eb3018b875324db612647c46' 
  AND token = 'sjOEK1W7mEMYUJeZnC9aPfwq+I70DtO/YMikGQpNdKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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