SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c5ca4007a0c8da4fa4df9dfbef9cfbfd7176268707fa888f1137ee57f8574ca' 
  AND token = 'Z5gQgwSWZ6hCtJ1hyk4N1s21gCOluldzrAEH9axRtTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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