SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a03811eaa3d97bb2876cbd6d882203a575272fcccc713fc5b32f0cd4a66f6e' 
  AND token = 'fVFdmNl0hLOflplfn9iN/CGskX4sbRXuYtjlzywwOJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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