SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2803e6105b41e26bdf40c04c563800edf6fa7f6ff5579bbfa4086d60196068df' 
  AND token = 'd2wJ8QCt7qYsPyQuYFfI+nAS7PLoHI4wplOsKfWfoy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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