SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7574068a98147b3f1688d0c28e1e897a2cf79ccb23b3aa84307ccd74bebec999' 
  AND token = 'xRsHFSSi4AIncAxjERbTsO9IB+ixXSbRhu8WHlo3KCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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