SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf193bd29b00e9a4236d71e8c9808d4ac807a38897decbbab12f25ebfefe68c6' 
  AND token = 'VVp/6lsTzdmRP//UwJeWin7vz9aT+CoMHoDtOlrpSf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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