SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114b9837ae8baaff349102eba15f0dfcd5c355954bc6602bb838189bd2070690' 
  AND token = 'chvCiMEKuGIWU0IC4YAOHwHi+UmL7h28UHsWCttDAc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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