SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e8ac13b9f318eaedc85a567b83dd8100c70d98b8d01645c3d4a5bbe55128a59' 
  AND token = 'S6QrvJC4MRQmnPCgwrhcDIaazfnAXkUbXK4DLM4XnBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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