SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44d23c2696c6755a050f8af1865628218735f4f581534899b105dbfe11facb7' 
  AND token = 't7BJhhs1uMCQxf/rxo39fnRbMRITpEN1Qv+vCEDwnDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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