SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79367d80dbca20ddcb02f82b0d62d1249cfc45595ad03885cd6bfef38faacc2f' 
  AND token = '594kJDnHaGd9haNx8qDs56xyjwy4OENQ04UYqfFXvxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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