SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bbbcbc61bc1f9f97ca3e51fa096d15794b09900d39d02195daec060e1939d31' 
  AND token = 'PlSPxmOrRw7b/J7wXVK3ptQBCfF0O6xTYkb4pIsjFy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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