SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b92883779031faff4e0c4482168efc406d07b6a70bf027f017fc81ef5f797bda' 
  AND token = 'CuLuY7wscF/Hmg0ax3weyQMzzci+Sqm/vs2WqAHahqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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