SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77fa9d58eef36fcae9a686293c25e1376e0ac1dc7f31012ba34617bddd6ee0a6' 
  AND token = 'Q/KuGPtPG2Hx4T0yUR8XaFB3YUNeAEp02YL3Rp/0omc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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