SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59973ca56a4fd8bd02ce4f1d0b5ba6a2cfd260f8ac0ed49bee7308246597820d' 
  AND token = 'bWPKGhlkPGM9lMrHLnG3YqrXuArfIZ8BeZdt6MyaPCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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