SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a9bdff399761e7266cb2d42b578feaf5d465f26360770ea3dc6f82e870a4efa' 
  AND token = 'GVrOEaOjQdnAIT9/0bD0c6h//bB70/kQAXGEoPgFHTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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