SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2740c05a98836d79efff39a0dcc341a19e27b3a591e63e8e04bb6413f17186c9' 
  AND token = 'mOdeZ2UrNQqfNnS2Y2MVqRRFiSUshfmLMkFB4hx9HiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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