SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '129a03d4d582596de2c5ab4ed55bde2f74520b39ce6bcc60022f5b63ee7e68cd' 
  AND token = 'g8hd4MsSmDXomdFuGj2SBuTOAZu68VFEqGj3UcnBAmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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