SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb7e0ce74641200f8346247cadf02456e09cfcbfa892a336b6c69912d916fc5' 
  AND token = 'rB22Bm9m4z364iIpQieEaF1o5upKKfyAfpN88fvltuE=' 
  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"
    }
  }
}