SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab728295fcade6eabd70b461081ef1a6235a5747d574beb17b702bfbf82ceb0d' 
  AND token = 'ZMjmRNzzHB99n3ZAzvwr7BFJTazP1XYUZWTc4BRh0EQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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