SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc3f24fdcce6b78775f38324d32e0f5080b05247542fac5352d746a069e4f736' 
  AND token = 'QdrF6T7xeO9xjM9sYIoiRCPuFGohX2R8A++UX4IuLUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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