SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7294460e95017f1baea454628f27dde1b547d8237aab75274d4794d789464033' 
  AND token = 'vwWMhZ3ApndSEiu5Cg9nO/KKQd3nJ+vOgM6xgD1nezY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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