SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3782179e2651b6f12f06512ff4cd89e9295203972f108bb3068be010b1e1f475' 
  AND token = 'RxS3egXeRwOOMsY8ALgFOW3Qos3TKidKv4MKr53k1Oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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