SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbf0fb6a3fef7da9674af94095de38ab5ed3c6f3a5ea05baa5b16c635b354c2a' 
  AND token = 'tGu2WIPj8bKZhfAx/fFhbFsIjxKOStMnhayGFwpaf2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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