SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '758a53a8c601307218851774eb22265d77ec9e33acfaa300b62c551ce8399ed6' 
  AND token = 'd5qFzTo4OCLmmYMkID8T/YtrtrDDLQbxDuRcVtNrBu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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