SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6196eedab01ca158cbea2f9c9799e14937211db4065ef60d29b5b5e5493732d' 
  AND token = 'nU2xPf+8F3eL7u8AD9aMR/cpES+CnY8huDuCl6Xu2K0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}