SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24a360d62c5fff6f8e097fa73a5f9a609f980139fffe22ada9d757c19402e0a2' 
  AND token = 'Fd+xnLLPCeSmPu9Jg2TEEcPpW88v3CCTlvMEvVth2p4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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