SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b8cd8de872baffaec16cbcbfc669838dd2d8e9f05a65c7e4128d78cdd7f150' 
  AND token = 'stmHp3DPwgao8M8aP5fNUGpiUyoqNRAgHUq2366PdCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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