SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6164158f5a0eb3527d820be95d3c8611c6abe7b6835329410d30d9364e3170a' 
  AND token = 'Vpx2K8wQemWwq3+yvbqu0PYVw4mtMLmixsEnKXy6Ikw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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