SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5758f925682c83dd0ebb0de0db4d519c2522e8cfd8a5320a0edae3eb9a23864' 
  AND token = 'Q9LYqzLDsSz/l61fwbrg51md0imy9TyfFmrEM3jCqU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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