SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f28a54f6feca50e5932f3bfaaafb5e583f1b036b6a79524645d010fc78ca3bd6' 
  AND token = 'FBZccwzeVIXEmAejuButNCbPK+cgkTs9/kpuZ30iR4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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