SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c654a42f836bd4a4ebef6675c9509c62ded3ce6084077e98c3363327c16cdf5c' 
  AND token = '9tjjKyD6eCuSlMJt49IFYmNtuEk6GBp9jqNRnvltoKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}