SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f87b723143b97eeba018d6a78c9d457ba9bfbc7272dc842a731833aebfc7b7e9' 
  AND token = 'V0LsBEZGoezaCrR4ClIisyx/0BETVskvzTx19Vch8is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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