SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae974709c1616fbb7f9cfb59e7eed0d40e330b13a49bf7440c1d6a6e8484299c' 
  AND token = 'PmvbWTw0hsWOJApjBIGgjIZoNwWU3cy1B0EAXzY/9QI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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