SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd0d5f5767fc7633cb1664a7da862a86eded44757d87df2ea69c6aec934296d2' 
  AND token = 'RS8wbxMWiezDehlbbO0GVI9lvtwqjEcE4Zr0yW4+FRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}