SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58538378635d25e469e5af93ddfd31798d4e2224605fec277030db38067435bb' 
  AND token = 'efRzizl2voUVHbjbGeprZs25KEn21FsnRad6bXeRA3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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